1. Field of the Invention
The present invention relates to a semiconductor-package measuring method for testing electrical characteristics of a semiconductor package by setting the semiconductor package individually into a measuring socket in the semiconductor-package inspecting step, to a measuring socket of a semiconductor package, and to a semiconductor package to be tested.
2. Description of the Related Art
Conventionally, the inspecting step of testing an IC package, which has been formed into an individual piece by molding the IC package onto a lead frame with a mold resin and then soldering the package onto the surface of the lead frame and lead-working the package, has been manually executed or automatically executed while the IC package was automatically carried. The inspecting step described below is automatically executed.
FIG. 7 is a view showing a conventional IC-package measuring method, and is a schematic sectional view of a measuring device viewed from a side thereof.
A test tray 2 mounting an IC package 1 is transported by a not-illustrated transporting mechanism and the IC package 1 is set to an inspection position at which a socket 3 is disposed. In this case, the IC package 1 is positioned to a position at which the distal end of a lead 4 of the IC package 1 contacts the distal end of a conductive socket pin 5 of the socket 3.
Then, a lead-holding portion 7 made of an insulator and provided for a lead holding mechanism 6 of the measuring device lowers from the upper side to lower the test tray 2 simultaneously with the IC package 1 and bring the distal end of the lead 4 of the IC package 1 into contact with an upper surface of the distal end of the socket pin 5.
The lead holding mechanism 6 stops at a position where the mechanism 6 contacts a stopper 8 of a lead holder provided for the socket 3. Thereby, the lead holding portion 7 stops at a position further down by a certain distance from a position where the portion 7 contacted the lead 4 of the IC package 1. A stroke of the lead holding mechanism 6 from a position at which the lead holding portion 7 contacts the inserted lead 4 of the IC package 1 to the stopper 8 is referred to as socket pushing distance B.
In this case, the lead 4 and socket pin 5 move from the position shown by a continuous line to the position shown by an alternate-long-and-short-dash line and the lead 4, socket pin 5, a conductive portion of the socket 3, and a contact 9 are electrically connected with a not-illustrated measuring device, and thereby electrical characteristics are measured.
FIGS. 8A and 8B are enlarged views of the portion A in FIG. 7, in which FIG. 8A shows a case when the lead 4 and socket pin 5 are present at the continuous-line position and FIG. 8B shows a case when the same are present at the alternate-long-and-short-dash-line position.
Solder residue 10 is solder deposited on the socket pin 5 when the lead 4 is set to the socket pin 5 as shown in FIG. 8A, which solder was used for solder-plating the surface of the lead 4 of the IC package 1 in a previous step.
In the conventional IC-package measuring method described above, however, the deposited solder residue 10 is shaved off at the distal end of the lead 4 as shown in FIG. 8B during the stroke of the socket pushing distance B.
The shaved-off solder residue 10 attaches to the surface of the lead 4 or between a plurality of the leads 4 to cause a problem that the IC package 1 is mis-measured and the operating rate of the measuring device is lowered.
To solve the above problem, the present invention measures electrical characteristics by bringing a measuring pin of a measuring arm of a measuring socket into contact with an end surface of a distal end of a lead of a semiconductor package.
In accordance with the present invention, because electrical characteristics are measured by bringing the measuring pin into contact with an end surface of the distal end of the lead, no solder residue is produced and thus IC packages are not mis-measured and the operating rate of the measuring device is improved.